Since switching to Mac, I've abandoned almost all of the programs that I used on Windows, with the exception of Microsoft Word. This is mainly because Word is so widely used by others, that I've effectively been "forced" to install it, even though I hardly use any other application in the Microsoft Office Suite.
This is frustrating for two main reasons: Office is expensive, and it takes up over 500MB of my hard drive. Luckily, there are a selection of free and highly accomplished alternative word processing apps for Mac, some of which not only handle Word documents, but that you may even find improve on Word itself.
Writer is part of OpenOffice, a cross platform multilingual Java-based office suite that's designed as a free replacement for Microsoft Office. Writer is the word processing component, letting you open and edit Word documents (including .docx), export to PDF, and use it as a WYSIWYG editor for creating web pages. Some prefer to install NeoOffice which has taken OpenOffice and customised the interface for Mac.
A better solution than Writer for those working on slower Macs, like Writer, AbiWord lets you open Word documents, save to .doc format, and export to both PDF and HTML. The disadvantage is that it doesn't support .docx format, and may sometimes alter the formatting in Word documents so that they appear slight skewed. For those working on older Macs though, it's an excellent alternative.
Designed specifically for Macs, Bean is based on Cocoa, so it looks great. Bean can also open and save in Word format but note that it can't handle footnotes, images or pre-defined styles, and is only partially compatible with Word's file formats. In addition, it doesn't work with .docx, hyperlinks are imported as text, and exporting tables doesn't work well. In terms of speed, however, Bean is excellent.
Google's online office suite is handy replacement for opening and saving Word documents. All you need is a Google account to get started. Google Drive features a clean interface, autosave feature, spell check and it can save your documents either to your account, publish it as a web page or automatically e-mail it as a Word document. You can even invite others to collaborate with you on a document.
The ThinkFree Office suite isn't free, but it's online counterpart, ThinkFree Online, is. It only allows you to open and view any kind of Office document, including .doc and .docx and then embed, convert, share, upload or search them for free. You can perform basic functions for free but you have to sign-up for extra features such as the offline file management "Power Tool".
If you're looking to open Word Documents on Mac, check out these options.